Histological and immunohistochemical analysis of initial and early osseous integration at chemically modified and conventional SLA titanium implants: preliminary results of a pilot study in dogs

OBJECTIVES: The aim of the present pilot study was to investigate initial and early tissue reactions to modified (mod) and conventional sand-blasted, large grit and acid-etched (SLA) titanium implants. MATERIAL AND METHODS: Implantation of modSLA and SLA implants was performed bilaterally in both the mandible and maxilla of dogs. The animals were sacrificed after a healing period of 1, 4, 7 and 14 days, respectively. Peri-implant tissue reactions were assessed in non-decalcified tissue sections using conventional histology (Toluidine blue-TB and Masson Goldner Trichrome stain-MG) and immunohistochemistry using monoclonal antibodies to transglutaminase II (TG) (angiogenesis) and osteocalcin (OC). Bone density (BD) and bone to implant contact (BIC) were assessed histomorphometrically. RESULTS: Day 1 revealed an early TG antigen reactivity in the provisional fibrin matrix adjacent to both implant surfaces. Day 4 was characterized by the formation of a collagen-rich connective tissue (MG), which revealed the first signs of OC synthesis adjacent to modSLA surfaces. Immunohistochemical staining for TG revealed a direct correlation between angiogenesis and new bone formation, which was clearly identifiable after 7 days by means of increasing BD, BIC and OC values. After 14 days, modSLA surfaces seemed to be surrounded by a firmly attached mature, parallel-fibered woven bone. CONCLUSIONS: Within the limits of the present study, it might be concluded that the combination of immunohistochemical and conventional histological stainings in non-decalcified tissue sections is a valuable technique to evaluate the initial and early stages of wound healing around endosseous titanium implants.     

Effect of bone sialoprotein and collagen coating on cell attachment to TICER and pure titanium implant surfaces

To improve integration between implants and biological tissues, this study compared bone sialoprotein (BSP) as a surface-coating material against the major organic and inorganic components of bone, collagen type I and hydroxyapatite (TICER). The expression of osteocalcin, osteonectin and transforming growth factor ss was evaluated using immunohistochemical staining procedures. The distribution patterns of osteoblasts on the surface of pure titanium with a smooth machined surface and a rough surface (TICER) were determined by image processing using confocal laser scanning microscopy. The results compared to uncoated control materials showed that, at all times investigated, the number of cells on the surface of the TICER and pure titanium samples differed significantly (P<0.1), demonstrating the superiority of TICER over pure titanium in this respect. For pure titanium implants, collagen-precoated surfaces were not beneficial for the attachment of bone-derived cells with the exception of day 3 in vitro (P<0.01). BSP-precoated implant surfaces displayed non-significantly higher numbers of settled cells. BSP-precoated implant surfaces were beneficial for osteoinduction as revealed by osteocalcin and osteonectin expression. BSP precoating of the rough TICER implant surface enhanced the osteoinductive effect much more than did collagen precoating. These results contribute to the consideration of at least two distinct pathways of osseointegration.     

利用阻生智齿预备钛金属冠改善下颌义齿固位的应用观察

目的:利用阻生智齿增加下颌单颌总义齿固位力。方法:通过手术暴露下颌阻生智齿,在智齿冠上预备牙体,制作钛金属套冠将阻生齿牙冠形态转移至口腔中,从而把固位力不足的下颌单颌总义齿修复,转变成有正常基牙固位的可摘局部义齿修复。结果:通过3例利用埋伏阻生智齿接钛金属套冠,对下颌牙槽嵴严重吸患者的可摘局部义齿修复,经2～3年的临床观察,钛套冠固定良好,无松动,牙龈正常。可摘局部义齿固位良好。结论:利用埋伏阻生智齿接钛金属套冠,加强下颌牙槽嵴严重吸收可摘局部义齿固位力的效果明显。     

Production of transforming growth factor beta1 and prostaglandin E2 by osteoblast-like cells cultured on titanium surfaces blasted with TiO2 particles

The surface roughness of an implant to which osteoblasts attach may influence endogenous expression of growth factor and cytokines at the implant-tissue interface, modulating the healing process and affecting the quality of bone formation. The present study, using cells derived from human mandibular bone, investigated the effect of varying roughness of titanium surfaces on production of transforming growth factor beta1 (TGF-beta1) and prostaglandin E2 (PGE2). The titanium surfaces were turned (control) and then roughened by blasting with 63-90 micro m, 106-180 micro m or 180-300 micro m TiO2 particles. The cells were cultured onto the surfaces till confluence was achieved. Fresh media were added in the presence or absence of 1,25-dihydroxyvitamin D3[1,25-(OH)2D3], the stimulator of osteogenic differentiation, and aliquots of conditioned cell media were used for assay 24 h later. Cellular morphology was determined by scanning electron microscopy. Cellular production of TGF-beta1 and PGE2 on each surface was assessed by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), respectively, using commercially available kits. All blasted surfaces showed significantly higher production of TGF-beta1 than the turned surfaces (P < 0.05). In response to stimulation by 1,25-(OH)2D3 cellular production of TGF-beta1, was also significantly greater (P < 0.05) on the blasted surfaces than on the turned one. The total amount of PGE2 in the conditioned media was higher than on the turned surfaces in the presence or absence of 1,25-(OH)2D3. There were no significant differences among the three blasted surfaces with respect to production of the local factors. However, we could not show a synergistic effect of surface roughness and vitamin D on the production of both TGF-beta1 and PGE2 using primary cell culture model.     

Prospective study on titanium bar-retained overdentures: 2-year results

Within a monometallic concept 29 patients received titanium bar‐retained mandibular overdentures on 2 IMZ implants. The study had a prospective design with 3 months recall intervals. One of 58 implants failed after 11 months. There were no significant differences of the mean plaque scores (Silness, Löe) and the mean sulcus bleeding scores (Mühlemann, Son) at the abutments between baseline, 12 months and 24 months. Less than 40% of the subjects showed plaque score zero at 24 months. However, 89% exhibited sulcus bleeding score zero indicating health of the peri‐implant soft tissues in most cases. Plaque at the basal site of the bar was scored separately at additional measuring points located at the central area and the contact areas between bar and abutments. Bar plaque scores nearly doubled between baseline and 12 months and remained high at 24 months. Median maximal vertical bone loss around the implants was 1.7 mm after 2 years. Bone loss did not exceed one quarter of the implant length in 79%. The monometallic concept in bar‐retained overdentures on 2 implants proved its clinical suitability except for the applicability of pure titanium for bar clips. Plaque formation beneath the bar seems to be one of the major clinical problems.     

克氏针钢丝与髌骨针钛缆两种张力带固定治疗髌骨骨折

目的比较克氏针钢丝与髌骨针钛缆张力带固定治疗髌骨骨折的疗效。方法将128例髌骨骨折患者按固定方式分为A组(克氏针钢丝张力带固定,65例)和B组(髌骨针钛缆张力带固定,63例)。比较两组住院费用、住院天数、并发症发生率以及关节功能优良率。结果患者均获得随访,时间12~24个月。两组住院费用、住院天数、并发症发生率比较差异均有统计学意义(P<0.05)。两组关节功能优良率比较差异无统计学意义(P>0.05)。结论克氏针钢丝张力带固定术后并发症发生率较高,但关节功能优良率与髌骨针钛缆张力带固定比较无明显差异,且具有缩短住院时间、降低住院费用等优点。     

Biocompatible implant mimicking cartilage: A new horizon for reconstructive facial field

Cartilage is avascular with limited to no regenerative capacity, so its loss could be a challenge for reconstructive surgery. Current treatment options for damaged cartilage are also limited. In this aspect there is a tremendous need to develop an ideal cartilage-mimicking biomaterial that could repair maxillofacial defects. Considering this fact in this study we have prepared twelve silicone-based materials (using Silicone 40, 60, and 80) reinforced with hydroxyapatite, tri-calcium phosphate, and titanium dioxide which itself has proven their efficacy in several studies and able to complement the shortcomings of using silicones. Among the mechanical properties (Young’s modulus, tensile strength, percent elongation, and hardness), hardness of Silicone-40 showed similarities with goat ear (P > .05). Silicone peaks have been detected in FTIR. Both AFM morphology and SEM images of the samples confirmed more roughed surfaces. All the materials were nonhemolytic in hemocompatibility tests, but among the twelve materials S2, S3, S5, and S6 showed the least hemolysis. For all tested bacterial strains, adherence was lower on each material than that grown on the plain industrial silicone material which was used as a positive control. S2, S3, S5, and S6 samples were selected as the best based on mechanical characterizations, surface characterizations, in vitro hemocompatibility tests and bacterial adherence activity. So, outcomes of this present study would be promising when developing ideal cartilage-mimicking biocomposites and their emerging applications to treat maxillofacial defects due to cartilage damage.     

3D打印钛网预成形联合术后严密护理对眼眶爆裂骨折患者预后的影响

目的:探讨3D打印钛网预成形联合术后严密护理对眼眶爆裂骨折患者预后情况的影响。方法:选取笔者医院收治的眼眶爆裂性骨折患者122例,随机分为对照组和观察组,分别62例和60例。对照组患者予以常规钛网置入术,观察组患者予以3D打印钛网预成形,术后均予以视力监测、眼肌运动训练等严密护理。观察并比较两组患者钛网贴合度,复视、眼球运动及眼球突出等症状的改善情况。结果:观察组患者CT矢状位上修复眼眶底的钛网呈S形,对照组患者呈弯向眼眶内的弧形。术后3个月、6个月,观察组患者复视、眼球运动受限情况治愈率均高于对照组,差异具有统计学意义(P<0.05);术后,两组患者患眼眼球突出度差值均降低,观察组显著低于对照组,差异具有统计学意义(P<0.05)。结论:3D打印钛网预成形与眼眶爆裂性骨折患者眶底契合度更高,联合术后严密护理对复视、眼球运动受限及眼球突出等症状的改善作用更好,患者预后更好。